ZnO纳米线的横向生长及其紫外性能研究

发布时间：2018-01-07 03:22

本文关键词：ZnO纳米线的横向生长及其紫外性能研究　出处：《重庆大学》2015年硕士论文　论文类型：学位论文

【摘要】：ZnO是一种宽禁带半导体,因其特殊的光学和电学性能而被广泛应用在传感器、太阳能电池等领域。同时,伴随现代信息存储和半导体加工技术的不断发展,对器件的构筑单元的要求越来越小。例如,以ZnO纳米线结构为基础的纳米技术己向器件集成的方向发展。但是由于ZnO纳米线的尺寸非常小,利用常规的微纳加工技术构造ZnO纳米器件已经成为关键性难题,并最终导致了ZnO纳米线在探测器的发展方面受到了严重的制约。本文针对这一问题,采用化学气相沉积法在硅衬底电极上成功制备出横向ZnO纳米线,从而实现了ZnO纳米线网状电路的制备,并对影响纳米线生长的因素及相应的紫外光传感性能进行了研究,具体包括如下三部分:第一部分主要围绕生长时间、压强、反应源料的形态及配比等因素对纳米线生长的影响展开研究,以期通过控制生长时间、气氛的压强、反应源料的形态及配比来控制纳米线的合成。通过对生长时间、压力、物料比等对ZnO在柱状电极侧边周围形核机制和纳米网进行考察,我们发现随着生长时间延长ZnO纳米线的长度不断增长;压强的增大会使纳米线的密度变大;使用纳米金刚石作为碳源制备ZnO纳米线时,反应速率大大提高,与石墨相比,相同时间内制备的ZnO纳米线阵列的密度和尺寸更大。ZnO与金刚石的比例为4:1时,所制备出的ZnO纳米线阵列最为理想。同时,通过对石墨和纳米金刚石的物性进行比较分析,纳米金刚石作为碳源制备ZnO时的反应速率较快的原因是纳米金刚石具有更大的比表面积和较低的活化温度,使得其与ZnO的反应更加充分从而提高了反应速率。第二部分主要围绕基于柱状电极的ZnO纳米线网状电路的生长机制及其紫外光传感性能进行研究。基于可控合成ZnO纳米线的研究,首先采用微纳加工的技术构筑了单晶硅(50í50μm)柱状电极,并以此柱状电极为衬底制备横向ZnO纳米结构;其次,将刻蚀好的Si基板正面朝下放置在源材料(ZnO粉和石墨粉)的上方,并控制蒸汽流和腔内压强就成功地合成了横向生长的ZnO纳米网;再次,通过对纳米线形核生长过程的分析表明导致纳米线在电极的边沿处横向生长形成纳米网的主要原因是:一是电极的边沿部具有较高的结合能,另一个是在柱状电极的边沿处物料蒸汽的浓度较大。最后,将纳米网电路进行器件化并对其紫外敏感性能进行了研究,在紫外光照射时,表现出较好的光学敏感性能。第三部分主要围绕基板和电极机构优化以提高紫外光传性能展开工作。我们以金刚石为碳源在条状光栅电极上制备ZnO纳米线样品,并对其进行紫外光传感测试。研究结果表明:在桥接电路中,ZnO纳米线桥的暗电流为10-9数量级,而光电流在10-7数量级,光增益达57倍。
[Abstract]:ZnO is a wide bandgap semiconductor, because of its special optical and electrical properties and is widely used in sensors, solar cells and other fields. At the same time, with the continuous development of modern information storage and processing technology of semiconductor devices, the construction unit requires more and more small. For example, the ZnO nanowire based nano structure technology has direction device integration development. But because the ZnO nanowires are small in size, the use of conventional micro nano structure machining technology of ZnO nano devices has become a key problem, and ultimately led to the ZnO nanowire is restricted in detector development. Aiming at this problem, by chemical vapor the deposition method was successfully prepared by transverse ZnO nanowires on silicon substrate electrode, so as to realize the ZnO nano wire mesh circuit fabrication, and influence factors on growth of nanowires and the corresponding UV light. The perceptual can are studied, including the following three parts: the first part mainly focuses on the growth time, pressure, study effect of source material morphology and composition and other factors on the growth of nanowires, in order to control the growth time, atmosphere pressure, synthetic form and ratio of reaction source material to control the nanowires through the pressure on the growth time, material, investigation of ZnO in cylindrical electrode side around the nucleation mechanism and nano net ratio, we found that with the growth time of ZnO nanowires growing in length; the increase of pressure will make the Nanowire Density Change; the use of nano diamond as carbon source for the preparation of ZnO the nanowires, the reaction rate is greatly improved, compared with graphite, the same time the system size and density of ZnO nanowire arrays prepared more.ZnO diamond and the ratio was 4:1, the ZnO nanowires were prepared for the array Want to. At the same time, through the comparative analysis on physical properties of nano diamond and graphite, nano diamond as carbon source for preparing ZnO the rapid reaction rate because nano diamond has larger specific surface area and low activation temperature, the reaction of ZnO and more fully so as to improve the reaction rate of second. Part mainly focuses on the research of growth mechanism of ZnO nanowire column electrode network circuit and its sensing properties based on UV. Research on controllable synthesis of ZnO nanowires based on the micro nano processing technology to build a monocrystalline silicon (50, 50 m) cylindrical electrode, and the cylindrical electrode for transverse ZnO nanostructures the substrate system; secondly, the Si substrate facing the etching placed in the source material (ZnO powder and graphite powder) above, and control the steam flow and cavity pressure the successful synthesis of the lateral growth of ZnO nano network again; Second, through the analysis of the nuclear growth process showed that the main cause of the linear nano nano line electrode is formed on the lateral growth of nano network is: one is the combination of edge electrode has high energy, the other one is the concentration in the edge of the material steam columnar electrode is large. Finally, the circuit nano network devices and the UV sensitive properties were investigated under UV irradiation, show optical sensitive good performance. The third part focuses on the optimization of the electrode substrate and institutions in order to improve the UV transfer performance work. We use diamond as carbon source for preparing ZnO nanowires in strip grating electrode, and UV sensing to test it. The results show that: in the bridge circuit, the dark current of ZnO nanowire bridge for 10-9 magnitude, and the photocurrent in the level of 10-7, the optical gain of up to 57 times.

【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB383.1;O614.241

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